This information is part of the Modelica Standard Library maintained by the Modelica Association.

This example shows a way to look at the traveling wave moving along a power line.

This wave can be seen looking at intermediate points of the line, looking at both OLine (several segments per line trunk) and TLine models.

OLine in the lossless case is less accurate, since shows oscillations that are not present in a distributed parameter line but, since it allows the addition of resistances and conductances, allows evaluation of losses.

Suggested tests:

7 segments per trunk, lossless

Run the model as it is. Since resistances and conductances are very small in OLine, the simulation is substantially lossless.

Show in the same plot ramp.y, oLine1.p2.v, oLine2.p2.v, oLine3.p2.v, oLine4.p2.v.

Show in another plot, simultaneously, ramp.y, tLine1.p2.v, tLine2.p2.v, tLine3.p2.v, tLine4.p2.v. Here oLine shows unreal oscillations, which, however, reduce if the number of segments per trunk increases.

50 segments per trunk, lossless

Try increasing this number from 7 to 50 using parameter segsPerTrunk, and look at the same plots as per test 1

50 segments per trunk, losses

Leave segsPerTrunk=50, change r1 to 1e-3 Ω, re-simulate: the effect of losses is visible only on the oLine plot.

• May, 2021 implemented by Massimo Ceraolo, University of Pisa